Rotary drill



I July 7, 1936. E. N. KERSEY 2,046,915

ROTARY DRILL Filed Feb. 17, 1936 Patented July 7, 1936 UNITED STATES PATENT OFFICE ROTARY DRILL Earl N. Kersey, Panuco, Mexico, assignor to Mexica-n Gulf Oil Company, Wilmington, Del., a corporation of Delaware Application February .17, 1936, Serial No. 64,397

,6 Claims.

and removal of adhering matter from their interiors. If the interior .ofeach section is to be cleaned to the full diameter of its bore, it becomes necessary to employ a reamer with a .cut ting blade which may be passed in a retracted position through the narrow portion of the bore near the joints andthen extended to the full internal diameter of the pipe when the upset is passed. .At the same time, the nature of the reaming operation requires that the reaming tool be of sturdy and durable construction. Drill pipe sections are usually thirty feet in length, while their internal diameters may be anywhere from two .to slightly less than eight inches at the full portion of the bore and anywhere from one and. seven-sixteenths to six and.

five-eighths inches at the narrowest portion of the upset. tool for the reaming operation.

Prior to my invention, expansible cutters or reamers have been used in this operation, but their design and construction leaves much to be desired in the way of simplicity and durability. Most prior tools are designed in such a way that the reaming blades are extended or retracted through a complicated linkage of mechanical actuating elements extending from -the cutting blade to the rear of the tool body. Such complicated mechanism in a tool of this type detracts from the sturdiness of construction of the whole tool and is in itself extremely vulnerable to failure from wear or strain. In addition, it is uneconomical to manufacture.

An achieved object of this invention is the provision of a rotary reaming tool of simple and durable construction having a retractable reaming blade extendible by a simple and compact once-acting mechanism and retractable by the force of gravity alone.

A further achieved object of the invention is the provision of a rotary reaming tool having a retractable reaming blade in combination with a fixed drill or cutter of less diameter, whereby when the reaming operation iscommenced at Such small bores require a compact.

one end of a pipe section to be cleaned, it may becontinued until the entire section is cleaned.

The invention will best be understood by consideration of the following detailed description of a specific embodiment thereof in view of the accompanying drawing wherein:

Fig. l is a partly sectional isometric view of a rotary reaming tool embodying my invention andhaving a retractable reamingblade in combination with a fixed drill bit, the blade being shown locked in extended position;

Fig. 2 is a side elevation of the same tool; Fig. 3 is an elevation taken at right angles to Fig. 2;

Fig. 4 is a detail isometrioview of the reaming blade removed from its position in the tool; and Fig.5 is a fragmental side elevation with the sleeve removed from looking position and Show: ing the cutter in dotted lines in retracted.

position.

Referring to the drawing, reference character 1 indicates in general a metal tool body of tubular shape, threaded at the rear as at '2 and having a longitudinal slot 3 near the forward end. At the forward extremity, a diamond point bit 4 is shown securely welded to the tool body I. A bore 5 extends from the rear of slot 3 to the rear extremity of the tool body. A two-edged cutting blade 6 is rotatably mounted within slot 3 by means of pivot pin 1 extending across slot 3 and carried by the tool body I The dimensions of blade 6 are such thatwhen it is longitudinally disposed with respect to the tool body I, it is accommodated within slot 3, but when transversely disposed, it extends outwardly on either side, being of length greater than the width of the tool body, as shown in Figs. 1 and 2. Pin 8 attached to the cutter near one cutting edge, and pin 9, near the forward end of slot 3, form complementary means adapted to cause cutter 6 to rotate from the retracted to the extended position when connected by an elastic member such as the rubber band Ill shown in Figs. 1 and 3. A bar II extending across slot 3 forms a stop to prevent rotation of the cutting blade 6 past the extended position under the influence of the elastic ii]. Advantageously, the tool body is strengthened adjacent the slot 3 by a reinforcing shoulder l2 either made integral with the tool body or welded thereto. Locking sleeve I3 is movable over the rear portion of the too-l body 1 andis provided with recesses M at its forward end in which the rear edge of cutting blade 6 is received when the sleeve 13 is in the foremost or locking position. As shown in Figs. 1, 2 and 3, the looking sleeve I3, when forwardly positioned, abuts the rear edge of cutter 5 to prevent retraction during the cutting operation. A threaded coupling I5 engages the threads on the rear of tool body I to hold sleeve I3 in the locking position and to form means for coupling tool body I to another section of pipe (not shown) through which the tool is rotated or held during the cutting operation hereinafter described.

The details of the cutting blade 6 are best shown in Fig. 4, wherein reference character It indicates a journal for the pivot pin I. Channels I'I form water courses to permit water from bore 5 to progress to the forward edge of the cutter in order to lubricate the cutter and drill bit and carry away cuttings. The blade is formed with cutting edges I8 and I9 on each end and is beveled away approaching these surfaces. The forward entering edge of the cutter is generally indicated at 29 and the rearward edge at 2|. The journal I6 while equidistant from opposite cutting edges I8 is disposed nearer the relatively light forward edge 20 than the heavier rearward edge 2! with the result that when the blade 6 is journaled on the pivot pin I and the pivot pin approaches a horizontal position, the blade, under the influence of gravity alone, will tend to come to rest with its length horizontally disposed and the rear edge 2| lowermost.

The operation of the device is as follows:

In reaming set cement from the interior of a thirty-foot section of internal upset drill pipe, the reaming tool described may advantageously be driven by a core machine with a hydraulically operated head in the horizontal position. I have successfully performed such an operation in the field by coupling tool body I with a longer section of pipe through coupling I5 to form an elongated drill rod. To the end of the drill rod opposite the coupling I5 a swivel is attached for supplying water through bore 5 at high pressure. The core machine may be of the type ordinarily used for driving a core drill in the taking of shallow rock core samples in conjunction with the drilling of an oil well. The section of pipe to be cleaned out is placed horizontally on blocks at the same elevation as the drill. Chain tongs are used to keep the pipe from turning.

The cleaning operation is started by drilling into the pipe for fifteen or eighteen inches with a diamond point bit alone to get beyond the narrow portion of the bore at the joint. When this is completed the bit is withdrawn and the thin shell of cement remaining is cleaned out with chisels and bars to form a bore of sufficient diameter to permit initial extension and locking of the cutter blade 6 when the reamer is introduced. With elastic II] in place over pins 8 and 9, coupling I5 is unscrewed sufficiently to permit locking sleeve I3 to move far enough to the rear for cutter 6 to rotate within slot 3. The cutter blade 6 is then rotated to the retracted position within slot 3 and held there while the forward end of the tool is inserted in the cleaned out portion of the pipe to be reamed. After passing the narrow portion of the bore at the upset, the cutting blade 6 is extended by the action of pins 8 and 9 and elastic I0; after which the locking sleeve I3 is again moved forward to the position shown in Fig. 1 and held there by tightening the coupling I5. The coring machine is then started to actuate the reamer and the reaming operation continued until the narrow portion is reached at the other end of the thirty-foot section of pipe being cleaned. During the reaming operation the elastic I0 is destroyed.

The use of the diamond point bit 4 in combination with the reaming blade 6 makes it possible to clean out the narrow portion of the bore at the far end of the pipe being reamed in the same operation as the reaming of the full bore.

When the reaming operation is complete and it is desired to withdraw the tool, coupling I5 is unscrewed and the locking sleeve I3 pulled rearwardly far enough to permit blade 6 to rotate on pivot I. The tool is then turned until the pivot pin I is in a horizontal position with stop II above it. The blade 6 then falls into the slot 3 under the infiuence of gravity alone (as shown in Fig. 5) and the entire tool may be easily withdrawn through the narrow portion of the bore near the joint.

If a hydraulic core machine is not available for use as an actuating mechanism, the pipe to be cleaned may be chucked up in a lathe and the reamer and rod held stationary. In such an operation the swivel for supplying water may be dispensed with as the hose may be directly connected to the rear of the drill rod.

While I have described in detail the operation of the reamer of my invention only in its application to the cleaning of internal upset drill pipe, the invention is not to be taken as so limited as other useful application of the device will appear obvious to skilled mechanics. Likewise, I have described in detail the advantageous combination of the reamer construction with the fixed bit, but it is to be understood that I contemplate as within the purview of my invention that embodiment in which the reamer is in itself the complete tool.

The invention is not limited to the specific embodiment illustrated and described, as various changes may be made without departure from the scope of the appended claims.

What I claim is:-

1. In a rotary drill, a body member having a drill bit carried at one end thereof, a longitudinal slot extending through said body member near the same end, a cutting blade of greater length than the width of said bit but of no greater width than said bit, said blade being pivoted to said body in such a manner as to be retracted within said slot in one position and to be extended outwardly on each side of the body member in cutting position when rotated on said pivot, said pivot being so placed with respect to the center of gravity of said cutter blade as to cause the blade to tend to come to rest in a retracted position at one horizontal position of said body member, means to rotate said cutter into cutting position from a retracted position and releasable locking means for holding said cutter in the extended position while cutting.

2. In a rotary drill, a body member carrying a drill bit of greater width at the forward end thereof, a longitudinal slot extending through said body member near the same end and adapted to accommodate a reaming blade, a pinextending across said slot and carried by said body member, a reaming blade pivoted on said pin and adapted to rotate in said slot, the length of said blade being greater than the width of said bit, and the width of said blade being no greater than the width of said bit, the pivot point being disposed equidistant from the cutting 75 ends of the blade but away from the center of gravity thereof whereby when the tool body is in a horizontal position and the pivot pin approaches the horizontal, the reaming blade will tend to come to rest in a retracted position in said slot, complementary means on said body member and said reaming blade adapted when connected by an elastic member to rotate said blade from a retracted to an extended position with respect to said body member, a stop to prevent said reaming blade turning beyond the extended position and means for releasably locking said reaming blade in the extended position.

3. In a rotary drill comprising a rotary tool body carrying a bit of greater width at the forward end, means for increasing the diameter of bore produced comprising a two-edged cutting blade of length greater than the width of said bit, a slot extending through said tool body and adapted to accommodate said cutting blade, means pivotally connecting said cutting blade to said tool body so that said blade may rotate from a retracted position parallel to said body and within said slot to an extended position at right angles to said body, means for moving said blade from the retracted to extended position and releasablelocking means for maintaining the blade in the extended position while cutting, said pivotal means being so placed with respect to the center of gravity of said blade as to cause the blade to fall back from an extended position to a retracted position under the influence of gravity at one horizontal position of said tool body when said locking means are released whereby said drill may be introduced and removed through a hole of less diameter than the length of said cutting blade.

4. In a rotary drill a body member having a drill bit carried at one end thereof, a longitudinal slot extending through said body member near the same end, a bore extending through said body member from the rear of said slot to the rear extremity of the body member, a two-edged reaming blade pivoted to said body member at a point equidistant from its two cutting edges and adapted to rotate within said slot so as to be in a retracted position when parallel to said body member and to be extended when at right angles thereto, said pivot being so disposed with respect to the cutting blade as to cause the blade to fall back from an extended position to a retracted position under the influence of gravity at one horizontal position of said tool body, complementary means on said body member and said blade adapted to cause the blade to rotate from the retracted to the extended position when connected by an elastic member, an elastic member connecting said complementary means and adapted to be removed therefrom by the drilling operation, a stop on said body member to prevent rotation of said cutting blade beyond the extended position under the influence of said elastic member, a sleeve movable over the rear end of said tool body and adapted when in a forward position to lock said reaming blade against rotation and releasable means for maintaining said sleeve in a forward position with respect to said tool body.

5. In a reamer, a body member having a longitudinal slot near one end, a two-edged reaming blade pivoted to said body member in such a manner as to be retracted within said slot in one position and to be extended outwardly on either side thereof in cutting position when rotated on said pivot, complementary means on said body and said blade adapted when connected by an elastic member to rotate said blade into cutting position from the retracted position, an elastic member connecting said complementary means and adapted to be removed by the reaming operation, a stop adapted to prevent said blade from turning beyond the extended position under theinfluence of said elastic member and releasable locking means to look said cutting blade in the extended cutting position, said pivot being so disposed with respect to said blade as to cause the blade to tend to fall back from the extended to the retracted position under the influence of gravity at one horizontal position of said body member.

6. A reamer comprising a rotary body member having a longitudinal slot near one end, a pivot pin extending across said slot, a reaming blade pivoted on said pin and adapted to be retracted within said slot in a longitudinal position and to extend outwardly on either side of the body member when rotated around said pivot to a transverse position, the pivot point being equidistant from the cutting edges of said blade but being away from the center of gravity whereby at one horizontal position of said body member said blade will tend to come to rest in a retracted position under the influence of gravity, means to rotate said reaming blade on said pivot from the retracted to the extended position and releasable means to lock said blade in the extended position.

EARL N. KERSEY.' 

